【作者】 赵文光；

【导师】 田一光；

【作者基本信息】 温州大学 ， 应用化学， 2010， 硕士

【摘要】 白光LED灯具有节能、环保、寿命长等优点,是替代白炽灯和荧光灯的新一代半导体光源。在白光LED的三种实现方式中,单管芯波长转换型是白光LED的主流技术,常见的有蓝光芯片与YAG荧光粉匹配和近紫外芯片与RGB三基色荧光粉匹配两种模式,近年来又开发了近紫外芯片和单基质白光荧光粉匹配的W-LED。由于使用荧光粉与LED组合实现白光成本较低,色稳定性较好,工艺重复性好成为目前新型照明光源的研究重点。以硅酸盐为基质的发光材料由于具有良好的化学稳定性和热稳定性,合成工艺简单,原料廉价、易得等优点,成为发光材料新的研究热点。本论文主要采用常压高温固相法制备Eu²⁺掺杂的MAl₂Si₂O₈ （M=Ca, Sr, Ba）荧光体,通过物相组成和晶胞参数变化与光谱特性关系的研究,得出了Eu²⁺掺杂的碱土金属铝硅酸盐荧光体中组成、晶体结构与光谱特性的定量和半定量关系,一些规律性结果为白光LED发光材料的研究提供了科学参考数据。首先以具有钙长石结构的CaAl₂Si₂O₈为基质,用Sr²⁺,Ba²⁺,Mg²⁺等与基质晶格中的Ca²⁺进行单离子置换,对单离子置换的化合物物相组成,晶体结构和光谱特性进行分析,结果表明Sr²⁺可以完全替代Ca²⁺形成连续固溶体,各固溶体试样的晶胞参数和发射光谱峰位均与阳离子置换量成线性变化;而Ba²⁺,Mg²⁺与钙长石则只能形成部分固溶体。用Mg²⁺、Sr²⁺、Ba²⁺其中两种离子的组合对Ca²⁺进行双离子置换后,在一定的置换范围内可以形成连续固溶体,在固溶体组成范围内,其晶胞参数和光谱特性也呈现出规律性的变化。对锶长石结构的SrAl₂Si₂O₈基质组成进行Ba²⁺,Mg²⁺单离子置换。结果表明Ba²⁺与Sr²⁺在全组成范围内形成连续固溶体,试样的晶胞参数和发射光谱峰位亦成线性变化规律;用Ca²⁺,Ba²⁺,Mg²⁺的组合进行双离子置换的结果表明,这些离子在锶长石中与在钙长石为基质时相比有更大的固溶范围,固溶体试样的晶胞参数和发光光谱呈现规律性变化。更多还原

【Abstract】 Due to its energy savings, positive environment effects, long service time, white light emitting diodes are described as a new generation of solid-state lighting devices. Among the three methods of white LED realization, the wavelength conversion type of single tube core is the main mainstream technology, more common type include blue emitting chips matched with YAG phosphors and near ultraviolet chips matched with tricolored phosphorescent powder. In recent years it has developed near-UV chip and single-phased full-color emitting phosphor which matched with W-LED. Due to its low cost, good color stability and excellent process reproducibility, it has become a research emphasis of new illumination light source. Eu²⁺ activated silicate phosphor becomes a researching focus for its good thermal and chemical stabilities, simple synthesis technology and cheap & available raw material.Eu²⁺ adopted MAl₂Si₂O₈ （M=Ca, Sr, Ba） phosphor were prepared by traditional solid state method. And by means of researching the relationship between phase composition and crystal structure, and luminescence properties, the quantitative and half-quantitative relations between the compositions, crystal structure and luminescence properties of Eu²⁺ activated alkaline earth aluminosilicate were obtained. The exploration of inherent law has provided scientific reference for obtaining high performance and white light-emitting materials.Firstly, the influence of some aspects on the crystal constitution and luminescence performance of Eu²⁺-activited anorthite has been investigated, such as the substitution of part of feldspar cation for Sr²⁺, Ba²⁺, Mg²⁺ ions. The analysis of crystal structure and luminescence performance shows that Sr²⁺ ions can completely replace Ca²⁺ ions to form a continuous solid solution. The lattice parameter of samples and emission spectra have a linear relationship with the concentration of Sr²⁺ substitution in the range 0.1～0.9 mol/mol, however, Ba²⁺, Mg²⁺ can only form a part of the solid solution. When with Mg²⁺, Sr²⁺, Ba²⁺ ions combinations of pairs of ion-exchange, continuous solid solution can be formed within a certain range, in which lattice parameters and emission spectra also displayed regular variation.And then the influence of some aspects on the crystal constitution and luminescence performance of Eu²⁺-activited anorthite has been investigated, such as the substitution of parts of feldspar cation for Ba²⁺, Mg²⁺ ions. The analysis results of phase composition, crystal structure and luminescence properties show that Ba²⁺ ions can completely replace Sr²⁺ ions to form a continuous solid solution. The lattice parameters of samples and emission spectra of peaks are also present linear variation with Ba²⁺ ions content. When with Ca²⁺, Ba²⁺, Mg²⁺ ions combinations of pairs of ion-exchange, the results show that these ions, which in strontium feldspar solid, has a greater solid solution range ,in which the cell parameters and the luminescence spectra of these phosphors also showed regular change.更多还原